Insufficient rear wheel traction is a well known restriction inherent in the fundamental design of many cargo hauling vehicles including standard, as well as compact pick-up trucks. This is due to the inherent relative light weight of the cargo area when unloaded since this area encompasses the area directly over the driving rear axle. Without the benefit of loaded cargo, the weight over the rear axle of the vehicle is simply insufficient to provide adequate traction for the rear wheels. This restriction or shortcoming in the design of the vehicles results from the consumer's desire, indeed demand, to have a standard size, light weight vehicle that is economical to drive during periods in which it is unloaded. At the same time, access to the full length and width of the cargo area is demanded when there is a full pay load to be hauled. The need for adequate traction when the cargo area is unloaded is of increased importance during inclement weather, such as in rainy, snowy, or icy conditions; i.e. traction problems are especially prevalent when the road surface is slippery.
To overcome this restriction, many vehicle owners simply add ballast weight in the cargo area of the vehicle in an effort to improve rear wheel traction. Typically, this additional weight takes the form of randomly placed cargo, such as sandbags, concrete blocks, firewood, snow or any other readily available items.
Although this self help method is simple to implement and inexpensive, it is also inefficient and possibly damaging to the vehicle. This random placement of the cargo is most often simply either stacked against the tail end of the cargo area, or against the front of the cargo area adjacent the cab. Further, simply placing the added cargo in the middle of the cargo area allows it to be free to slide to one of these locations during braking or acceleration. This is not only very annoying to the occupants of the vehicle, but also can result in substantial damage to the cargo area. As will be realized, having the ballast cargo in either of these locations does help to then restrain its longitudinal movement in at least one direction, but in terms of assisting in increasing the traction, it is very inefficient. Since the cargo is not directly over the rear axle, only a portion of the desired additional weight is transferred to the rear axle.
In response to this operational restriction of cargo hauling vehicles, and the inadequacy of this most popular self help method for improving traction, several designs for ballast cargo restraining or securing devices have been attempted. While these designs are a move in the right direction, they fall short when it comes to securing the ballast cargo against sliding in all directions in the cargo area. Also, there is a need for a new design of a traction enhancing device of this type, that is not only capable in restraining the cargo in all directions, but is easier and more convenient to install and remove, is low in cost and adaptable for use with auxiliary pay load cargo holders.
One prior art traction enhancer design is disclosed in U.S. Pat. No. 4,482,169 to Yim, which includes two transverse supports sized for placement on the bed of a truck between the wheel wells. Lead weights are bolted to the supports to form a rectangular assembly. In one embodiment, wooden extensions are extended beyond the space between the wheel wells. The extensions contact either the front or the back side of the wheel well to prevent movement of the assembly in only one direction.
This type of traction enhancer assembly has several disadvantages. First, assembling the transverse supports and lead weights to form the rack assembly is a difficult and cumbersome process. The transverse supports are preferably bolted to six one-hundred pound lead ingots, which are not only hard to find but are very expensive. Once configured for use, the weight of the assembly makes the rack difficult to manipulate. During installation and removal, the use of a forklift is required.
Further, the assembly is not entirely secure and therefore not efficient during use. The wooden extensions on the transverse supports are located on only the front side or the back side of the wheel wells. This configuration allows the rack assembly to move away from the most efficient position directly over the rear axle during use. This movement is also likely to cause damage to the bed of the truck.
Another traction enhancing system is disclosed in U.S. Pat. No. 4,902,038 to Grover. A system of interlocking rectangular cast iron plates are positioned on the bed of a truck in a manner which allows for the normal use of the truck bed. This system of interlocking plates is intended to provide additional weight to improve traction.
While this type of prior art system provides the advantage of allowing substantially the full use of the bed of the truck for transporting cargo, the system is also high in cost and not easy to install or remove. Also, the added weight is dispersed throughout the truck bed and not focused directly over the rear axle in the most efficient manner.
Thus, there is a need identified for a vehicle traction enhancing apparatus that provides ballast weight on the cargo area over the rear axle that is efficient in restraining the weight directly over the rear axle, and that is easy to use and low in cost.